Cyril, Oklahoma, sits in USDA hardiness zone 7b — a zone band wide enough that plant choice, not possibility, is the interesting question.
Among the crops suited to this profile: cabbage, prickly pear, california poppy, and collard greens. The site-level story — soil, sun, drainage — decides the rest.
Even in Cyril, no two yards are alike.
A low spot, a south-facing slope, or a stand of trees moves the frost date and sun across a single Cyril lot. Enter your address and we'll score 1,086 plants against your land's actual soil, sun, and frost.
We read public map data around Cyril — soil, climate, flood, and parcel records. How we handle your address.
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Cyril — the short answer
Cyril, Oklahoma: USDA zone 7b, about 243 days between hard freezes, across 367 acres of town.
- USDA zone
- 7b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 16
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 14
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~243
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 367 acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are this town’s own 28°F normals: light frosts run a few weeks past them, and tender transplants usually wait 2–3 weeks after the last hard freeze.
Hardiness Zone Range
Zone 7b is Cyril's average, not your lot's — a low corner or a tree line moves it. Against Cyril's 243-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Cyril
Each reading below is measured for Cyril itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredCyril runs about 243 days between hard freezes — a long growing season.
There is slack for succession plantings and slow-finishing crops: many vegetables can be sown twice, and the heat-lovers have time to ripen fully.
Plan a second sowing of quick crops after the first comes out, and use the fall window most gardeners let sit idle.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredCyril sits in USDA hardiness zone 7b.
The zone sets which perennials, shrubs, and fruit trees live through an average winter here — a plant rated for a colder zone is a safe bet, one rated warmer needs winter protection or gets treated as an annual.
Match perennials and fruit to the zone before you buy, so nothing you plant is a gamble against the cold.
USDA PHZM 2023
The kind of country Cyril is in
Cyril sits in the Central Great Plains — EPA Level III, inside the wider Great Plains. That is read at Cyril's own centroid rather than borrowed from Caddo County.
What Grows in Cyril
Every plant below cleared Cyril's own zone 7b and its 243-day season. Each card opens that plant's Oklahoma profile. How we score.
Is it too late to plant in Cyril?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Feb 16; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 16 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 14 — long-season crops need about 90 days of runway, quick greens only 30. There is slack in a calendar like this — late plantings, second rounds of favorites, and a fall bench that keeps beds working.
What's on the federal record near Cyril
Closest first, within ~10 miles of Cyril. Listing isn't leaking, and distance isn't exposure.
- TEPPCO CRUDE OIL STATIONBrownfields · 250 ft
- Lee Gibson Dba Gibson Oil CoUnderground Storage Tanks · 400 ft
- JohnsonsUnderground Storage Tanks · 550 ft
- Mac's Quick MartUnderground Storage Tanks · 700 ft
- CYRIL PETROCHEMICAL CORPBrownfields · 750 ft
- Country MartUnderground Storage Tanks · 1100 ft
- A. F. Wass Labor & Hardware, InUnderground Storage Tanks · 1100 ft
- Soni's Food MartUnderground Storage Tanks · 1200 ft
- Bill Malone Oil CompanyUnderground Storage Tanks · 1200 ft
- Oklahoma Refining Co.Underground Storage Tanks · 1400 ft
- Comanche Cyril Quick StopUnderground Storage Tanks · 1700 ft
- Gasoline AlleyUnderground Storage Tanks · 1700 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Cyril's center, not your beds. Run your own address for what's upwind of you specifically.
Environmental Intelligence
The counts behind that headline — every source type on the record near Cyril.
Sources Checked
within ~10 miles of Cyril
Severity Distribution
within ~10 miles of Cyril
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Cyril, two things run higher than the national average within ~10 miles of Cyril — Nitrate (88 sites) and Superfund (3 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Superfund: Superfund sites represent the most severe contamination in the federal system.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Check your specific parcel in Cyril
Get exact proximity distances to contamination sources for your specific parcel — plus soil, sun, drainage, and 1,086 plant recommendations.
25+ data sources read at your address, not the Cyril average
Your land is one point inside Cyril
Everything above resolves to Cyril as a whole — one PHZM band and one 28°F frost record, read across 367 acres. Your parcel is one point inside that footprint. Slope, tree cover, a low spot that pools cold air, and what is in the soil are all resolved at the address, and none of them are visible at town scale. That is the honest boundary of this page, and the reason the next step is a reading of your own ground rather than a better local average.
Your Lot vs the Cyril Average
Cyril Average
- ●USDA Zones 7b, averaged across Cyril
- ●One soil character for all of Cyril
- ●Frost dates read at Cyril's scale: Mar 16 to Nov 14
YOUR Parcel
- ✓Your exact zone, not Cyril's 7b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Cyril
Pull a site-specific report for your exact address in Cyril, Oklahoma — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Cyril averages can't show:
We read public map data around Cyril — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Cyril average
How we know this about Cyril
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this town’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Cyril’s own record; boundaries and acreage from US Census TIGER/Line 2025; the contamination records from the federal sources named in their beats above. Soil is not read at town grain anywhere on this page — there is no town-resolution survey in our data, which is why you will find no soil grid here rather than a statewide one wearing a local label. The resolution ledger below names every figure this page inherited.
Common questions about Cyril
When does frost risk typically end in Cyril?
The last hard freeze (28°F) in Cyril typically lands around Mar 16, per NOAA 1991–2020 climate normals — earlier than the light-frost dates most charts quote. That marks the hard freeze, not the last light frost — lighter frosts keep biting past it, which is why tender transplants here wait until about Apr 6.
When is the first frost in Cyril?
The first hard freeze (28°F) in Cyril typically arrives around Nov 14, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 31, so the watching starts about Oct 15 — about 243 days after the spring freeze cleared.
How long is the growing season in Cyril?
Measured between 28°F hard freezes, Cyril sees about 243 frost-free days — roughly Mar 16 through Nov 14, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 6 to Oct 31, about 208 days.
Is the soil safe to grow vegetables in Cyril?
The federal record around Cyril is a meaningful one — 155 documented sites, mostly Nitrate entries (88), the nearest Brownfields record under a tenth of a mile out — so a soil test before new food beds is a sensible precaution here, not a reason to hold back from growing. Remember that proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what sits where.
How do I protect my plants from frost in Cyril?
From about Oct 15 the job here turns from planting to protecting — the last start even a 30-day crop can finish. As the season closes around the first 28°F hard freeze near Nov 14 (NOAA 1991–2020 climate normals), three moves buy time: row cover or an old sheet over tender plants on still, clear nights; water the soil the afternoon before a freeze, so it holds warmth overnight; and harvest tomatoes, peppers and basil before Nov 14. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Cyril's scale — its 7b band and its 243-day season. Your yard writes its own version of Cyril's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
What this page reads at Cyril’s own scale
6 of the readings below were taken at Cyril's own scale — its own ~243-day season between 28°F freezes, the 367 acres it covers and 155 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Cyril's own USDA hardiness band, zones 7bUSDA PHZM 2023
- Cyril's own 28°F hard-freeze dates, about Mar 16 and Nov 14 and the ~243-day span between themNOAA 1991–2020 Climate Normals
- 155 documented contamination sites on the federal record near Cyril, the closest Brownfields record under a tenth of a mile out from the town centreFederal environmental registers
- Cyril's boundary and the 367 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7b and a ~243-day seasonGrowable Ground crop-matching engine
- The ecoregion at Cyril's own centroid, the Central Great PlainsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Cyril's 367 acres read through its county's SSURGO summaryfrom Caddo County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Caddo County
- The growing challenges every Oklahoma grower plans around — written at state scale, so they stay on the state guidefrom Oklahoma
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Caddo County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Cyril's 367 acreswhy one lot differs from the next →
- Which side of Cyril you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 367 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record under a tenth of a mile out, measured from the town centrehow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — measured at your address, and averaged away by any Cyril-wide figureread your own land →
More in Oklahoma
Wider growing context
What grows across OklahomaCyril sits outside our named growing regions, so Oklahoma as a whole is its closest context here.
Nearby growing guides